Created
April 19, 2015 19:52
-
-
Save jacquesattack/83765d754bd59d1135f8 to your computer and use it in GitHub Desktop.
Benchmarking in R: pre-allocated vectors vs vector concatenation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| f1 = function(n){ | |
| x = double(n) | |
| for(i in 1:n) x[i] = runif(1) | |
| return(x) | |
| } | |
| f2 = function(n){ | |
| x = c() | |
| for(i in 1:n) x = c(x,runif(1)) | |
| return(x) | |
| } | |
| n = 1000 | |
| microbenchmark( | |
| f1(n), | |
| f2(n) | |
| ) | |
| ## As you see, they are virtually the same, which was surpring to me. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment